There are described in EP-A-0 388 062 various absorbent materials of the type comprising a non-woven fibre sheet having a dense surface layer of fibres at each face of the sheet and, between the surface layers, a relatively low density region which, apart from an initial "tacking" operation, has not been subjected to any substantial needling. More particularly the preferred materials there described each comprise at least a major proportion of hydrophilic fibres, although there is also a passing reference therein to the possibility of producing absorbent material entirely of hydrophobic fibres. The preferred materials described in said specification utilised in particular a mixture of hydrophilic and hydrophobic fibres, the hydrophilic fibres serving to absorb fluids while the hydrophobic fibres provided a "scaffolding" for retaining the structure of the low density region, even under compression. In the case of the wholly hydrophobic fibre material, the fluid is believed to have been effectively "stored" within the structure rather than being absorbed into the fibres themselves.
Although the absorbent materials described in detail in said specification have in practice proved generally satisfactory, nevertheless when fluid has been absorbed by the hydrophilic fibres in the web there arises a tendency in these hydrophilic fibres to collapse, especially under compression, so that although the use of hydrophilic fibres is believed to enhance absorbency, absorbent webs including hydrophilic fibres may tend to collapse and thus have a less than optimum absorbency and may even "wet back" when a load is applied, that is the absorbed fluid may be forced out of the material by the pressure.